function stop = outfun(x, optimValues, state)
% fct this function is called at each step of the optimization process
% x : the point computed by the algorithm at the current iteration.
% optimValues : is a structure containing data from the current iteration.
% state : current state of the algorithm.
% Written by Philippe Lucidarme
% https://www.lucidarme.me
figure (1);
plot3 (x(1),x(2),optimValues.fval,'.k','MarkerSize',10);
stop=false;